meson: convert vss-win32

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/qga/meson.build b/qga/meson.build
index 3513a90..9ddb260 100644
--- a/qga/meson.build
+++ b/qga/meson.build
@@ -44,3 +44,9 @@
                  link_args: config_host['LIBS_QGA'].split(),
                  dependencies: [qemuutil, libudev],
                  install: true)
+
+if targetos == 'windows'
+  if 'CONFIG_QGA_VSS' in config_host
+    subdir('vss-win32')
+  endif
+endif